DETROIT (AP)  Authorities temporarily closed a stretch of highway in Detroit on Monday to search for shell casings or other clues in the apparently random shooting of four vehicles last week.

About two miles of westbound Interstate 94 on Detroit”s east side was shut down as police searched for evidence that could lead to an arrest in Thursday”s shootings, which wounded one driver who was shot in the leg. Police dogs also were to be used to search for shell casings, state police Lt. Michael Shaw said.

“For us, this is basically our last opportunity to take a walk through there to make sure we got everything and make sure that we didn”t miss anything,” Shaw said, noting that it would likely be the last search of the roads because snow was expected and would have to be plowed.

Police called off a planned search Monday of a part of I-96 on the city”s west side where two of the shootings occurred due to the falling snow and safety concerns.

Investigators have said they believe the shootings are linked. But Shaw said investigators don”t believe they”re dealing with a situation like one in which two-dozen vehicles were shot at along I-96 and nearby roads between Lansing and Detroit over a three-day period in 2012.

An area man, Raulie Casteel, of Wixom, was sentenced in 2014 to prison on terrorism and weapons charges for those attacks and also is serving time for a related case in Oakland County. Defense attorney Doug Mullkoff, said the geologist was mentally ill and was “very troubled” at the time of the shootings.

“That was multiple shootings on multiple days in multiple locations,” Shaw said. “This is one incident that involved four victims.”

The motives behind the Detroit shootings could be varied and include someone who was “mad at the world for about a half-hour,” Shaw said.